NEW YORK (CNN) -- Speaker after speaker Monday evening at the Republican National Convention said that President Bush's decisive declaration at one of the scenes of the terror attacks of September 11, 2001, demonstrated the need to re-elect him.

Monday night, former New York Mayor Rudy Giuliani recalled that when Bush visited the rubble of the twin towers September 14, 2001, the president declared, "They will hear from us."

And Giuliani asked, "As long as George Bush is president, is there any doubt they will continue to hear from us?"

Giuliani said it doesn't matter to Bush "how he is demonized. It doesn't matter what the media does to ridicule him or misinterpret him or defeat him."

"They ridiculed Winston Churchill. They belittled Ronald Reagan. But like President Bush, they were optimists. Leaders need to be optimists. Their vision is beyond the present, and it's set on a future of real peace and security.

"Some call it stubbornness. I call it principled leadership."

The ex-mayor, the widow of a passenger on one of the flights and New York's former top cop recounted the terrorist attacks during their stints at the podium to remind viewers and convention delegates of a time when the nation in crisis rallied behind the president.

Like the Democratic National Convention, the Republican gathering featured a tribute and moment of silence for those who died in the terror attacks nearly three years ago.

In a night built on the theme "A Nation of Courage," the GOP used the attacks and the pre-emptive assault on Iraq to return to its strategy of portraying Bush as avenging and determined, and his Democratic opponent, Sen. John Kerry, as accommodating and indecisive.

"President Bush sees world terrorism for the evil that it is," said Giuliani, the night's final speaker. "John Kerry has no such clear, precise and consistent vision. (Transcript)

"It is important to see the contrast in approach between the two men: President Bush, a leader who is willing to stick with difficult decisions even as public opinion shifts; and John Kerry, whose record in elected office suggests a man who changes his position often, even on important issues."

"The contrasts are dramatic. They involve very different views of how to deal with terrorism. President Bush will make certain that we are combating terrorism at the source, beyond our shores, so we can reduce the risk of having to confront it in the streets of New York," Giuliani said. "John Kerry's record of inconsistent positions on combating terrorism gives us no confidence he'll pursue such a determined course."

Despite his support for Bush, Giuliani has acknowledged disagreements with his party over abortion, same-sex unions, gun control and stem-cell research.

Democrats have criticized Republican convention planners for scheduling prime-time speakers such as Giuliani, New York Gov. George Pataki and California Gov. Arnold Schwarzenegger, who, they say, do not represent the Bush-Cheney ticket on significant social issues.

Sen. Hillary Rodham Clinton of New York called it a "bait-and-switch" convention.

Earlier, Sen. John McCain of Arizona, who is popular among independents and has frequently opposed Bush administration policies, defended the president's decision to wage pre-emptive war in Iraq. (Transcript)

McCain also took a swipe at filmmaker Michael Moore, who is attending the convention.

"Our choice wasn't between a benign status quo and the bloodshed of war," McCain said. It was between war and a graver threat. Don't let anyone tell you otherwise. Not our critics abroad. Not our political opponents. And certainly not a disingenuous filmmaker." (Full story)

The crowd responded with rowdy boos directed at Moore and a chant of "four more years." Moore's film "Fahrenheit 9/11" criticizes the Bush administration's actions since the terrorist attacks of September 11, 2001, and has been roundly condemned by conservatives.

Before and after a video montage of U.S. weaponry and warships played against a choral backdrop of military anthems and marching songs, speakers lauded President Bush's leadership.

Earlier, Bernard Kerik, the former New York police chief who commanded officers on September 11, said Bush demonstrated strong and decisive leadership after nearly 3,000 died that day. And he said Bush's subsequent actions have proved his boldness.

"As I think about his leadership, I think of the courage it took for our commander in chief to land on an airstrip in the dark of night, a world away, to be with our troops on Thanksgiving," Kerik said about Bush's surprise visit to Baghdad in November.

"He was there for them as he was for us right here in New York City, inspiring a nation as he stood on hallowed ground, supporting the first responders. This fight against terrorism takes decisiveness, not contradiction," Kerik said, referring to the Republicans' contention that Kerry changes his position on important issues.

It was Rep. Dennis Hastert of Illinois who fired the first partisan salvo early in the evening. Interrupting the roll call of states, he criticized Kerry's stance on the economy and the war in Iraq.

"[Kerry] is on the wrong side of taxation," Hastert said. "He's on the wrong side of litigation, and he's on the wrong side of regulation. These are job killers.

"This is no time to pick a leader who is weak on the war and wrong on taxes. George W. Bush is a strong leader with the right vision for America," Hastert continued.

Taking a dig at the Democratic convention theme of "Stronger at Home, Respected Around the World," Hastert quipped, "In order to be respected around the world you have to have the courage to stand up for America."

Much like the Republicans did during the Democratic convention in Boston, Massachusetts, Democrats have placed rapid-response teams -- which they're calling "truth squads" -- on hand to address the media all week long.